From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 79067DDE04 for ; Tue, 18 Dec 2007 11:40:46 +1100 (EST) Subject: Re: [PATCH] Implement pci_set_dma_mask() in terms of the dma_ops From: Benjamin Herrenschmidt To: Christoph Hellwig In-Reply-To: <20071217100248.GA8433@lst.de> References: <20071217100248.GA8433@lst.de> Content-Type: text/plain Date: Tue, 18 Dec 2007 11:40:22 +1100 Message-Id: <1197938422.13400.28.camel@pasglop> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, Paul Mackerras Reply-To: benh@kernel.crashing.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2007-12-17 at 11:02 +0100, Christoph Hellwig wrote: > On Mon, Dec 17, 2007 at 05:35:53PM +1100, Michael Ellerman wrote: > > To save adding a hook to the dma mapping ops, pci-set_consistent_dma_mask() > > simply calls the dma_set_mask() hook and then copies the new mask into > > dev.coherenet_dma_mask. > > How is this supposed to work? There are various devices around that > want different mask for coherent vs streaming dma mappings, and we need > to tell the iommu that we're setting it for either the former or the > latter. I don't think we ever supported that difference. Too broken HW for us. We don't use coherent_dma_mask for anything at the moment on powerpc. Ben.